A new life for a German mine: RWE is building a giant 236 MW energy storage facility

German energy company RWE has begun installing a large-scale energy storage facility at the Hambach open-cast lignite mine in North Rhine-Westphalia. With a capacity of 236 MW and storage capacity of 470 MWh, the installation marks another step in transforming the coal-mining region into a modern clean energy hub.

The construction of the large-scale battery near the municipality of Niederzier marks a new phase in the redevelopment of former mining land ahead of the planned complete phase-out of coal.

128 battery containers

A site for the project has already been prepared on the former mine premises, and deliveries of the first components have begun. RWE will install a total of 128 lithium-ion battery containers there. Commercial operation of the entire facility is scheduled to begin in 2027.

The new energy storage facility will perform the following functions:

• Ancillary services – primarily frequency regulation in the German power grid.
• Synthetic inertia – in the future, the system will provide so-called artificial grid inertia, helping to ensure the safe operation of a power system without traditional conventional power plants.

Hambach as a green energy hub

The German energy giant is currently developing battery projects across Germany with a total capacity of approximately 1.7 GW. However, the Hambach mine site is becoming a particularly important location on this map.

RWE has already commissioned three photovoltaic farms there with a combined capacity of approximately 50 MW, as well as a smaller battery storage facility rated at 4.1 MW / 8.1 MWh. At the same time, another 14.8 MW solar farm and an accompanying 80 MWh storage facility are under construction nearby. The new 236 MW installation will connect these projects into one of the largest renewable energy complexes in the region.